Rift just as many other MMOs has a day and night cycle. This change of light is also happening in dimensions. Of course, sometimes you want to set a certain atmosphere and having the day and night cycle interferes with this mood. If this is the case, there are dimension items that set your dimension to a specific time.
Be aware, though, that the item has a limited range, so in big dimensions, you may need to place several of those items. Thankfully, they are very cheap. Most of them are below one gold, the most expensive is well below 2 gold. For comparisons: My low level alt (level 17) has 18 platinum. Just buy the items off the auction house.
Before you go and buy those 24 items just to see which time of the day you actually want, just have a look at the gallery I made. I chose the Guardian faction’s starter dimension “Sanguine Shores” because it is small, free for every Guardian character, you get it when you’re very low level and it has a nice view with the horizon clearly visible and water to reflect the light as well as shadows from tree.
What you can’t see is the sun and the moon in those screenshots. They aren’t always visible, which is also because there are clouds in the sky. But I did get a few screenshots where you can see them above the water which makes for some pretty effects – well, who am I telling this to? I guess you all know what reflections of the sun and the moon can do to a scenery. :p